Is There a Sound Basis for
Deciding How Many Dentists Should Be Trained to Meet the Dental Needs of the Canadian
Population? Systematic Review of Literature (1968-1999)

 Gerardo Maupomé, CD, M.Sc., DDPH RCS(E), PhD


 H. Jack Hann, DDS, MPH, FRCD(C) 

 Jeannine M. Ray, BA, M.Sc. 

Abstract

A systematic review was conducted of the literature on human resources planning
(HRP) in dentistry in Canada, critically assessing the scientific strength of 1968-1999
publications. Inclusion and exclusion criteria were applied to 176 peer-reviewed
publications and grey literature reports. Thirty papers were subsequently
assessed for strength of design and relevance of evidence to objectively address HRP.
Twelve papers were position statements or experts reports not amenable for inclusion
in the system. Of the remaining 18 papers, 4 were classified as projections from
manpower-to-population ratios, 4 as dental practitioner opinion surveys, 8 as estimates of
requisite demand to absorb current capacity and 2 as need-based, demand-weighted studies.
Within the 30.5 years reviewed, 53.4% of papers were published between 1982 and 1987.
Overall, many papers called for a reduction in human resources, a message that dominated
HRP during the 1980s, or noted an increase in the demand for services. HRP publications
often had questionable strength or analytic frameworks. The paradigm of busyness-scarcity
evolved from a belief around an economic model for the profession into a fundamental tenet
of HRP. A formal analysis to establish its existence beyond arbitrary dentist:population
ratios has usually been lacking.

ecisions about the organization of health care services
should be based on state-of-the-art information on health technology, epidemiological
data, the effectiveness of treatment interventions and professional practices in specific
settings.1 Basic organizational aspects are the number and profile of
professionals that would meet the needs of a population. This issue has been a matter of
debate in Canada; symposia, task force groups, independent researchers and many dental
professionals have discussed it. However, it is not known how close we are to determining
the ideal number or mix of personnel required to serve an increasingly hetero geneous
population.2

One problem is the lack of an evaluation framework to assess the body of knowledge
addressing human resources planning (HRP) in dentistry. The most obvious solution is to
undertake a systematic review whereby the literature is appraised through a strict design
to make the review process more comprehensive, to minimize the chance of bias and to
strengthen its reliability.1

This study is a systematic review of the literature on HRP in Canada between 1968 and
1999.

Materials and Methods

This review was undertaken using primarily standard methods.1

The first step was to select databases for conducting the review. Initially, Medline,
Embase, Current Contents and Biological Abstracts were the electronic databases selected.
Once it had been established that they overlapped substantially, only Medline was used.
MeSH terms employed were dentistry, dental health services, dentists, dental staff, public
health dentistry, dental care, dental auxiliaries, dental hygienists and dental
assistants. Each of the terms was focused to trends, manpower, and supply and
distribution. All searches were then combined with the term Canada and
exploded to include all 10 provinces. A keyword search was also undertaken for
dentistry or dental or dentists plus the term manpower, subsequently combined with the
term Canada. Results were limited to the years 1968 to 1999.

Second, the references cited in relevant articles were searched by hand.

Third, since a great deal of grey literature was known to exist, a
catalogue search (non-serial publications) of the University of British Columbia library
system was undertaken. This university biomedical collection is the second largest in
Canada. The keyword searches were dentistry or dental or dentists or hygienists plus
manpower and Canada and 1968 to 1999. Before starting the search for publications, a data
extraction sheet was designed by 2 calibrated public health dentists from examples used in
other systematic reviews. The sheet was used in pilot trials and improved several times to
test operational definitions. An article was included in the review if it was (i) original
research, symposia proceedings, a position statement or an experts report addressing
the planning of human resources (HR) in dentistry and allied dental pro fessions in
Canada, (ii) written in English or French, (iii) published from January 1968 to July 1999
or (iv) part of the grey literature, i.e., not listed in mainstream databases
but published by a professional, governmental or scientific body. A publication was
excluded if it was (i) a case report, editorial, letter, news or comment, unless it
addressed in a meaningful way the evidence discussed in other included publications, or
(ii) a description of HR without a clear planning emphasis. After reviewing these
features, a decision was made to include or exclude a paper.

An inventory of included papers was developed according to the type of document, the
use of research methods (if applicable), the HRP factors involved, a summary of the study
design and the conclusions and recommendations implicitly or explicitly outlined. Papers
were classified according to their HRP approaches following the DeFriese and Barker3 system
(see Table 1). This system offers a critical
appraisal of the relative sophistication of the methodologies used in HRP studies. It
implicitly assumes that health needs and health care needs are met by dental personnel,
therefore relegating to a secondary position the impact of population-based interventions
or individual preventive strategies. The system does not take into account changes in
technology or shifts in the emphasis placed on underemployed preventive technologies.
Perhaps most importantly, the DeFriese and Barker system implies that dental education is
a product that is purchased almost independently of it being a means to improve health or
meeting demands for care of the population.

Data were analyzed as required using descriptive statistics and Spearmans rho
test.

Results

Of the 176 papers that resulted from the searches, 146 were reviewed and
eliminated. Only 30 papers were included in the review (see Tables 2 to 6 ).4-33
Eleven were position statements and one was an experts report not amenable to direct
inclusion in the DeFriese and Barker system (Table 2).
A further 9 experts reports, one symposium proceedings and 8 original research
papers were included in the system.3 Of these 18 papers, 4 were projections
from manpower-to-population ratios (Table 3), 4
were dental practitioner opinion surveys (Table 4),
and 8 were estimates of requisite demand to absorb current capacity (Table 5). While no econometric practice-productivity
studies were found, 2 need-based, demand-weighted studies (Table
6) were published in the 30.5-year interval. Half of the papers (53.4%) were
published during 1982 to 1987.

To establish whether studies published more recently had more sophisticated designs,
Spearmans rho analysis was done on the year of publication and the categories of the
system3 (excluding the 12 unclassified papers). We assumed that the higher the
category, the more sophisticated the design of the study. The rho coefficient was +0.472 (p
= 0.048), suggesting that more recent papers described more sophisticated approaches
in addressing HRP issues.

One of the most important items in this body of literature is the overall position
conveyed on the need to increase or decrease the HR supply. Thirteen papers (43.3%)
concluded that an HR oversupply might already exist or was about to occur at the time of
publication.9-13,15,17,18,20,24,28,29,32 Many of these reports called for a
specific reduction in HR for all of the schools. The need to protect the academic and
research capabilities of schools was emphasized by certain authors, indicating that it
would be preferable to reduce the number of schools than to implement a dramatic reduction
for entering students in each faculty.32 An increase in the demand for dental
services (insurance-generated) was also contemplated as a solution to the oversupply
problem. Eight papers (26.7%) indicated or implied that the HR were appropriate to their
evaluation framework or should be increased.7,8,19,21,23,25,27,33 A further 9
papers (30%) either did not offer an unequivocal statement about whether HR should
increase or decrease or offered both recommendations depending on different types of
personnel or situations.4-6,14,16,22,26,30,31 The small number of studies
precluded the use of a statistical test, but by charting the year of publication together
with the recommendation to increase or reduce HR, we concluded that papers lacking an
unequivocal statement were evenly distributed along the 30.5 years reviewed. Calls for
increases were more common in the 1970s and virtually ceased after 1985. Recommendations
to reduce HR started to appear in the late 1970s and became the dominant theme during the
1980s.

Discussion

It is not feasible to include every paper in a review of the literature. The
present approach offers a novel strategy to understanding HRP literature relevant to
Canada. It cannot, however, be considered an exhaustive processing of the information, as
some publications may have been omitted by virtue of the terms under which they were
listed in the databases. In other cases a subtle challenge was posed, in that certain
papers had a borderline status between the included and excluded categories. Furthermore,
the heterogeneity of reviewed studies made it infeasible to synthesize the findings in a
single measure (using meta-analytic techniques).

What are the methods used so far to estimate the number and profile of dental personnel
that should be trained? Tables 2 to 6 describe the various HRP factors and methods
that were contemplated in the papers reviewed. The factors are fairly comprehensive and
should allow a broad overview of the evolving HRP situation at the national or provincial
level. The main problem with the methods used so far is the questionable strength of the
majority of strategies selected: 73.3% of the documents are position statements,
experts reports or symposia proceedings. The largest individual category of papers
did not resort to a systematic approach to HRP (Table 2) as classified by DeFriese
and Barker.3 In the case of research papers, the scientific standards were
heterogeneous. While some designs were solid in their planning and undertaking,11,14,21
other papers were thinly disguised personal manifestos in which evidence, methods and
conclusions or recommendations were poorly related or lacked scientific rigor.12
A further group of papers failed to include information essential to understanding what
was actually done or assumed in the planning process,15-17 and it was therefore
difficult to fully evaluate their contributions. A great many assumptions and even hearsay
underlie this literature, suggesting that the main thrust of some documents was their
political or policy motivations. There is nothing intrinsically wrong with this feature:
HRP is not an apolitical enterprise.3 What is problematic is the generalized
assumption that in the absence of sound evidence, a perceived HR oversupply can be
considered a sufficient basis for closing dental schools or reducing enrolment, a
conclusion stated in 43.3% of papers. Similarly, an increase in HR should be driven by the
epidemiological profile and the features of the demand for services in the population.31
An argument to reduce dental personnel should not be based on fears of lack of busyness or
a deviation from an arbitrary dentist:population ratio. Resources available to support a
health care system are finite; choices have to be made to meet basic needs within a
clearly defined social contract.34

Where does this trend to reduce the HR supply come from? As a result of recommendations
made in the 1960s by the Royal Commission on Health Services, a policy was introduced to
expand dental HR. At that time, the clinical practice model, the technological state of
the art and the prevalence of oral morbidity and tooth mortality in the population offered
a large marketplace to dental practice. In this affluent environment, no real necessity
was perceived for planning the type of services needed or the health status goals that
would define success in professional endeavours. Many concepts had blurred boundaries
between access and demand, between health status and health care and between perceived
individual need and social responsibility. The dominant thinking was that an HR
undersupply would ensure a favourable marketplace in the future. We call such thinking the
paradigm of busyness-scarcity, i.e., a belief that as long as the number of dentists is
slightly less than what the market would bear, business will be good for the profession.
Such an economic model was accepted as part of a knowledge structure and an explanation of
reality.35 The professional discourse endorsing the paradigm became stronger
during the 1970s and was taken for granted in the 1980s, even though contradictions were
becoming apparent. As early as 1972, Lewis22 drew attention to the danger of
simplistic interpretations derived from the paradigm. An evaluation of the basis for such
a paradigm indicates that no formal analysis supported most papers. In many instances, the
reactive character of these documents emphasizes that no objective criteria were used to
define a given resources:demand relationship. DeFriese and Barker3 summarized
this shortcoming as follows: Planners and health professionals have a tendency to
see manpower as an end in itself, rather than a means to the attainment of more general
health goals. All too often, health manpower rather than the health-care services
that people seek is given primary emphasis in the planning process. The
conceptual simplicity of the paradigm and the inherent risk implied for dentists
income encouraged the professional associations32 and the planners15,17,18,30
to believe that the number of HR was the main problem that needed attention.
Such hegemonic ideology supported by repetition36 strengthened the paradigm,
and in so doing defined policies and political statements.

By acknowledging that one of the challenges to HRP is to preserve the social relevance
of, and social responsibility within, dental education, while evolving synchronously with
the needs of the population,37 it is feasible to recognize the necessity of
documenting the burden of illness as a prerequisite in the allocation of resources in HRP.3
Such documentation makes easier the task of distinguishing the advantages and
disadvantages of the different HRP methods. Overall, only 2 studies14,33
employed a clearly outlined research rationale coupled with an approach whereby the actual
needs and demands of the population were considered in HRP. As in other publications,
these 2 papers assumed that, in the absence of Canadian data accurately portraying
preventive and rehabilitative needs, American data could be used instead. There are no
Canada-wide epidemiological studies on oral health status. While this solution to
assessing needs is simple, it undermines the relevance of the analyses to the Canadian
scenario. Perhaps more importantly, it also highlights the paradox of Canadian society
spending $4.7 billion in dental care annually (1993 direct expenditures)38
without accurately establishing how those funds should be targeted or how successfully the
actual patterns of disease are being addressed. To place this expenditure in context,
similar figures for cancer and pregnancy costs were $3.2 and $2.0 billion, respectively.
Such lack of information precludes the undertaking of need-based, demand-weighted studies
that constitute the gold standard in HRP today. While Canadian epidemiological trends
suggest that decay experience and tooth loss are declining, it is still unclear how oral
care needs are changing across diverse groups. There are substantial treatment needs in
the younger groups in North America,39 and new cohorts of Canadians are
reaching old age with considerable treatment needs in more teeth.40

The foundations that we propose to support a more rational HRP process are, first, to
accept the necessity of conducting periodic national surveys to objectively determine oral
health needs and demands.9 Second, by negotiating the application of ethical
guidelines, it should be possible to agree on directives to allocate resources
effectively, to compensate providers fairly and to offer a reasonable range of services41
to maintain a functional level of oral health for the population at large. Finally, an
indirect result of the first 2 phases would be to define acceptable minimum standards for
oral health status and oral health care for the Canadian population through consensus by
professional, academic, governmental and lay stakeholders. Such standards should be
pertinent to the needs of the various age groups, culturally acceptable and subject to
cost-benefit analyses to determine their viability compared to alternative options. Such
options must objectively appraise the benefits and costs of implementing alternative
models of health care delivery.

Acknowledgments: We gratefully acknowledge the financial support of the S.
Wah Leung Endowment Fund, Vancouver, British Columbia. We also acknowledge the expert
observations and feedback of an anonymous reviewer to an earlier version of the
manuscript.

Dr. Maupomé is clinical assistant professor at the faculty of dentistry,
University of British Columbia, Vancouver, B.C., and investigator at the Center for Health
Research, Portland, Oregon.

Dr. Hann is professor emeritus at the faculty of dentistry, University of
British Columbia, Vancouver, B.C.

Ms. Ray is a fourth-year dental student in the faculty of dentistry, University
of British Columbia, Vancouver, B.C.

9. Boyd MA, Diggens J. The report of the joint committee of the dean of the faculty of
dentistry and the president of the College of Dental Surgeons of British Columbia. The
future of dentistry. British Columbia. 1987

27. Manning WG, Glazer AR, Kerluke KJ. Division of Health Services Research and
Development, Health Sciences Centre, University of British Columbia. Estimated available
positions for dental auxiliary manpower in British Columbia present and projected to 1980.
British Columbia; 1979.

The CDA Web site has statistics on the number of
dentists/specialists practising in Canada. The information can be found at: http://www.cda-adc.ca. Click on Practising
Dentistry, then on Number of dentists.